Lowering gearing

Jackle Posts: 10
edited May 2010 in Road beginners
I've just got myself a second-hand road bike, after using a MTB for years. I'm finding the gearing a little high for some of the hill climbs!

I've currently got a 39/53 on the front and 11-25 on the rear. I've been advised to change the rear cassette to a 11-27.

Would this be likely to make enough of a difference, and can I just change the rear cassette on it's own, or am I likely to suffer chain slip?


  • ALaPlage
    ALaPlage Posts: 732
    The rear cassette change will make a little difference and noticeable against the 25 tooth ring when you move to 27. In comparism to your MTB gearing though it will still be some way off. Perhaps consider changing off the double to a compact double which is typically a 50/34 at the front. The combination of 34 teeth at the front with the 25 at the rear (or 27 if you change the cassette too) will make a much bigger difference.

    Although you may be finding the climbs a little tough to start with (although they never get easier you just get quicker) you will find that using your curret set up will help with your strength and you do get used to it. Saying that I run an 11/28 rear cassette on a compact double :D

    Depends on the rear deraillieur set up and chain (I think) re chain slip if changing however any change will require the gears to be set-up properly, Get the local LBS to do it - mine charged me £5 to sort the gears out (adjustment).
    Trek Madone 5.9
    Kinesis Crosslight T4
  • 211dave112
    211dave112 Posts: 125
    check out the sticky thread...link http://www.bikeradar.com/forums/viewtop ... 8f514abd86
  • Mossrider
    Mossrider Posts: 226
    As the previous correspondent says - you will get used to it. I live in the Pennines and learned to be a roadie on a 39*25. I now use the equivalent of a 27 on the rear for serious sportives or trips to the Alpes, but a 25 for most other occasions. By all means get a new cassette (11*27? seems to give a lot of gaps - is a 13*26 or 14*27 available?).

    Changing to a compact is a whole lot more expensive...

    A few years back a 39*25 was seen as easy gearing for long days in the saddle....
  • John.T
    John.T Posts: 3,698
    If you are on Shimano then a 12/27 cassette will help with no real problem with gaps in the gears. You could also fit a 38 tooth inner ring.
  • ALaPlage
    ALaPlage Posts: 732
    I run Ultegra SL with an 11/28 rear cassettte. Shifts up and down smoothly and no different to the 12/25 cassette on a previous bike. I get the advantage of both gear extremes with the 11 handy to keep spinning down and off the descents and the 28 giving that little extra assistance when the climbs really start to hurt - plus it helps maintain the cadence on the hills.
    Trek Madone 5.9
    Kinesis Crosslight T4
  • Jackle
    Jackle Posts: 10
    Thanks for the replies. I'll be looking into getting a new cassette then.
    I've managed all the hills so far, even a couple on Exmoor, but some are a real struggle, so slightly lower gearing might help a bit..